1. Field of the Invention
The present invention relates to a system of electronic reprographics and, more particularly, to a method and apparatus for handling object faults in an electronic reprographic system.
2. Description of the Related Art
In electronic reprographic printing systems, a complex series of interactions occurs between the software services and objects and the hardware functions to provide the printed or otherwise processed end-product. In such a system, a document or series of documents comprising at least one print job are successively scanned, resulting in image signals which electronically stored. The signals are later read out successively and transferred to a printer for formation of the images on paper. Such a document can be printed any number of times or processed in any number of ways (e.g., words deleted or added; image magnified or reduced, etc.). If a plurality of documents comprise a job which is being processed, the processing or manipulation of the documents can include deletion of one or more documents, reordering of the documents into a desired order, or addition of a previously or subsequently scanned document or documents. The printing or processing can be relatively synchronous with scanning, or asynchronous after scanning. If asynchronous, a time interval exists between scanning and printing or processing. The system can then accumulate a number of scanned jobs in the system memory for subsequent processing or printing. The order of the job to be printed may be different from the order of jobs as scanned depending on the priority of the jobs and the desires of the operator for increasing productivity or through-put and decreasing printer or scanner down-time.
In such a system, the occurrence of faults on all levels of functioning can occur. Software object faults may occur to result in such faults as illegal job parameters, corrupted data, resource problems, input master errors, font problems, etc. Mechanisms for dealing with such faults are an integral and necessary component of the system, because such faults will result in the interruption of the system, and possibly a crash of the system which requires that the system be rebooted. Information from the system provided to the operator directing the operator to the fault or faults causing the job interruption is critical to the efficient operation of the system.
The related art has disclosed printing systems which provide object fault handling systems.
U.S. Pat. No. 4,745,602 to Morrell discloses a printer error and control system wherein errors are classified as either fatal or nonfatal system errors. A host terminal for the printer controls the printer and keeps track of errors. A fault light illuminates when an error occurs, and an error code is displayed. When a fatal error occurs, all functions within the printer are stopped until the fault is cleared.
U.S. Pat. No. 3,838,260 to Nelson discloses a microprogrammable control memory diagnostic system wherein fault reporting occurs continuously and is performed concurrently with normal program execution in a time-shared fashion. An error log is used to store error information which includes date and time of error, a job number affected by the error and a program status word and fault register content.
U.S. Pat. No. 4,514,846 to Federico et al. discloses a fault detection system which monitors the control of software crashes in a multiprocessor machine control system to prevent machine malfunctions, and provides a diagnostic path that isolates a particular control element in a multi-element control that contains a fault and then to a more comprehensive recording of the fault history for each individual control element.
U.S. Pat. No. 4,888,771 to Benignus et al. discloses a diagnostic configuration management system for a data processing system wherein failing options are isolated during a system checkout, a selected option checkout, or by resolving a missing option in the present configuration.
While the related art provides for the routine testing for and detection of errors and the recording of such errors in an error log, and for providing the operator with instructions regarding how to clear the fault, the prior art fails to disclose a mechanism which permits the system to report, and to allow clearance of, faults which occur in background functions that are transparent to the operator. Such a mechanism is desirable, because the detection and reporting of problems prior to a job's entry into the printer will prevent the necessitated cycle-down and the subsequent decrease in productivity. Furthermore, it is desirable that the operator be informed of faults in the system in such a manner that the operator can deal with the fault in a non-real time manner. This would allow the system to move on to a different job without requiring operator intervention, with the operator having the capability of fixing the problem at a more convenient time.